TARDIGRADA: CANADA 167 



Macrobiotus echinogenitus, Richters ? (27) 



This identification, being made from the egg alone, is somewhat uncertain. The 

 egg (Plate XXI. Fig. 58) is like that of M. areolatus (Fig. 53d), but is smaller, 

 and the spines are not separated by any space. 



Habitat. British Columbia and Ottawa. 



For a discussion of the affinities of this species with M. areolatus and other 

 related species, see below, under M. areolatus. 



Macrobiotus areolatus, sp. n. (Plate XXI. Figs. 53a-53e) 

 Synonym : M. echinogenitus, Richters, var. areolatus, Murray (19) 



Specific characters. Large, dark brown ; gullet wide ; teeth strong, bent near the 

 furca ; pharynx shortly oval, with apophyses, three narrow equal rods, and no comma ; 

 egg large, bearing very large conical processes, which are separated at their bases, 

 the surface between marked with irregular polygons which form a symmetrical 

 pattern. 



General description. The largest example measured was 700 ^ in length. The 

 egg measures about 100 /u. without the spines, 200 n over the spines, which, however, 

 vary considerably in length. Old individuals, as in most large species of the genus, 

 are strongly pigmented with a dingy brown colour, which is not disposed in such 

 regular bands as in M. oberhciuseri, but which still falls into obscure bands, prob- 

 ably caused by the disposition of the muscles and other structures in the skin. 

 The young are colourless and transparent. The gullet is somewhat constricted 

 towards the mouth and enlarged towards the pharynx, and bears the usual apophyses 

 on its end. The three linear rods are slightly curved and are nearly equal in length. 

 The stomach consists of few large cells. There is a pair of dark eyes. The claws 

 are in two similar pairs, which are united at the bases only, and diverge widely. 

 One claw of each pair is longer, and has supplementary points. 



Four unripe eggs have been seen in the body together. The shell of the egg is 

 thick, and of two layers. The reticulation which appears on the surface is produced 

 by the edges of septa which cross the space between the two layers. The areolation 

 appears to be originally regular hexagons, of which alternate ones bear processes, 

 The intermediate hexagons are each divided by a transverse septum, producing two 

 irregular pentagons. The turgidity of the processes further distorts and obscures 

 the regularity of the original hexagons. 



The areolation varies considerably. In one variety (Fig. 53f) the intermediate 

 hexagons are undivided and equal the processes in basal area. Some forms have all 

 the areolue rounded, and circular or elliptical. 



Owing to imperfect understanding of M. echinogenitus this species was at first 



